Monument Valley is the biggest prize in the latest Amazon app giveaway. The online retail giant has put $50 worth of paid Android apps and games on sale for the always-excellent price of free.

The clever Monument Valley game includes the add-on Ida’s Dream, which was formerly an in-app purchase. The Forgotten Shores addition will still cost $1.99, but it’s well worth it for the challenging and visually impressive game.

The story behind the story: About every few months Amazon puts a bunch of paid apps and games on sale. The goal is to get you to check out its alternative Amazon Appstore and get invested in the ecosystem. With a bunch of paid apps and games for free Amazon hopes you’ll buy future apps from them instead of Google Play.

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